Abrasive tools utilizing flapping tapes or straps extending radially from the hub are well known in the prior art. One such device known as “Fladder” uses rotating tools composed of layers of ring-shaped abrasive wheels which is the subject matter of U.S. Pat. No. 4,518,452, issued to Hundelbol with abrasive straps extending outwards radially and forming a cylindrical brush-like tool. A plurality of such rotary tools can be used simultaneously as discussed in U.S. Pat. No. 6,015,334, to achieve the highest efficiency and uniformity of material removal and at the same time provide for a simple method of accessing of all types of pockets, holes, edges and structural parts. This type of a tool is specifically desired in aerospace manufacturing processes and is extremely efficient.
There are a variety of abrasive brushes with bristle like abrasive extremities. For instance in United States publication No. 2008/0189923, assigned to 3M, an abrasive filament includes abrasive particles imbedded into a polymeric matrix which can be moulded. The United States application uses wires and rollers to hammer the surface and provide cleaning by impact.
U.S. Pat. No. 5,903,951, assigned to Minnesota Mining and Manufacturing Company provides moulded bristles.
U.S. Pat. Nos. 5,643,068 and 5,197,998 assigned to Minnesota Mining and Manufacturing Company and U.S. Pat. No. 5,125,192 assigned to Dynabrade, Inc., generally teach tools where abrasive filaments are provided as a stack of flat abrasive sheets of variety of shapes with slits separating it into strap like members.
In U.S. Pat. No. 5,423,718 assigned to Jason, Inc., grooves are provided in the direction of the length of an abrasive tool drum for insertion and anchoring of the folded abrasive sheets. Another example of a slotted support drum structure is described in U.S. Pat. No. 5,083,840, also assigned to Minnesota Mining and Manufacturing Company.
A variety of prior art references are related to utilization of helical patterns of winding of brush filaments around the drum, namely U.S. Pat. Nos. 3,688,335 by Clark and 2,782,439 by Ballard. The method for preparation of flattened brush filament and its winding is described in U.S. Pat. No. 2,294,480 by Rohweder et al.; an abrasive wheel with helical outer surface is described in U.S. Pat. No. 2,115,209 by Mulholland et al. U.S. Pat. No. 6,390,708 assigned to L'Oreal teaches a variety of helical grooves provided for fixation of brush bristles assemblies.
Folded abrasive filaments made from flat sheets and arranged into abrasive disks are described in U.S. Pat. No. 3,727,353, assigned to the United Aircraft Corporation.
One of the more common abrasive finishing wheels known from the prior art is a flap wheel. Typically, flap wheels are formed by a radial array of sheets of paper or rayon cloth with a layer of abrasive grit such as aluminium oxide resin bonded to one side. Such tools are useful for contoured polishing, cutting and blending of ferrous and non-ferrous metals, plastic and wood. However, such tools can only be run in one direction. The layer of adherent abrasive to one side of the cloth tends to wear the cloth or paper of the adjacent flap.
Limitations of such tools in the art remain due to their high cost, resulting from labour intensive manufacturing processes.
Turning now to methods of continuous manufacturing of such tools, U.S. Pat. No. 2,879,631, by Peterson teaches a brush and method of manufacturing, including steps of slitting the precursor sheet or tape of abrasive for providing abrasive straps, folding the precursor and mounting it on a support element by using the openings cut in the precursor close to the folding line, where the support element is then wound around the tool drum. Although useful, this method has operations of mounting the folded abrasive on additional support element, which are difficult to automate.
In U.S. Pat. No. 2,783,095, by Ballard, a method of forming a helical groove using rubber strap wound around brush drum is taught.
Finally, methods of describing abrasive sheets stacking or winding operations assisting cost reduction are presented in U.S. Pat. Nos. 2,626,414 and 5,922,160.
The prior art lacks instruction regarding an arrangement where a folded filament is wound around a drum in a helical pattern to provide an anchoring effect by buckling inside a supporting groove.
The present invention satisfies this need.